Java 将上下文传递给ListView的自定义适配器
我有一个名为Contacts的类,它接受来自另一个活动的数据并创建自定义ListView。我的困境在于我的CustomAdapter类。我尝试将活动上下文传递给CustomAdapter的构造函数。我试过了,用这个,联系人。这个都没用。我的所有小部件都不会使用适当的文本进行更新。所以我的自定义ListView将被加载,但那里什么都没有。相反,我传递了getApplicationContext()。这是可行的,但我必须在自定义适配器类中设置标志,我不确定这是否是最佳编程实践。首先,这是我的联系人活动文件Java 将上下文传递给ListView的自定义适配器,java,android,listview,Java,Android,Listview,我有一个名为Contacts的类,它接受来自另一个活动的数据并创建自定义ListView。我的困境在于我的CustomAdapter类。我尝试将活动上下文传递给CustomAdapter的构造函数。我试过了,用这个,联系人。这个都没用。我的所有小部件都不会使用适当的文本进行更新。所以我的自定义ListView将被加载,但那里什么都没有。相反,我传递了getApplicationContext()。这是可行的,但我必须在自定义适配器类中设置标志,我不确定这是否是最佳编程实践。首先,这是我的联系人活
public class Contacts extends AppCompatActivity implements View.OnClickListener {
private Button addContactBtn;
private ListView contactList;
private CustomAdapter customAdapter;
private ArrayList<String> names = new ArrayList<>();
private ArrayList<String> phoneNums = new ArrayList<>();
private ArrayList<String> emails = new ArrayList<>();
static final int REQUEST_CODE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_contacts);
addContactBtn = (Button)findViewById(R.id.contactAddButton);
contactList = (ListView)findViewById(R.id.contactList);
addContactBtn.setOnClickListener(this);
customAdapter = new CustomAdapter(getApplicationContext(),names,phoneNums,emails);
contactList.setAdapter(customAdapter);
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.contactAddButton:{
Intent i = new Intent(Contacts.this, AddContact.class);
startActivityForResult(i,REQUEST_CODE);
}
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode == REQUEST_CODE){
if(resultCode == RESULT_OK){
String name = data.getStringExtra("name");
String phone = data.getStringExtra("phone");
String email = data.getStringExtra("email");
phoneNums.add(phone);
names.add(name);
emails.add(email);
}
}
}
您正在使用
上下文调用另一个活动,因此它认为您正在尝试在活动外部调用,因此您需要使用标记标记活动新任务。
您可以尝试传递活动
。例如:
public CustomAdapter(Contacts activity,ArrayList<String>n, ArrayList<String>nums, ArrayList<String>e){
mActivity = activity;
phoneNumbers = nums;
names = n;
emails = e;
inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.customRowContactNumber:{
Intent i = new Intent(Intent.ACTION_DIAL);
mActivity.startActivity(i);//THIS IS THE ISSUE I THINK
break;
}
}
}
我试过了,用这个,通讯录。这个都没用?他们为什么不工作?对不起,我加在上面了
09-22 10:38:25.679 2794-2794/com.markfeldman.mydoggydays E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.markfeldman.mydoggydays, PID: 2794
android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
at android.app.ContextImpl.startActivity(ContextImpl.java:1238)
at android.app.ContextImpl.startActivity(ContextImpl.java:1225)
at android.content.ContextWrapper.startActivity(ContextWrapper.java:323)
at com.markfeldman.mydoggydays.CustomAdapter.onClick(CustomAdapter.java:73)
at android.view.View.performClick(View.java:4780)
at android.view.View$PerformClick.run(View.java:19866)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
public CustomAdapter(Contacts activity,ArrayList<String>n, ArrayList<String>nums, ArrayList<String>e){
mActivity = activity;
phoneNumbers = nums;
names = n;
emails = e;
inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.customRowContactNumber:{
Intent i = new Intent(Intent.ACTION_DIAL);
mActivity.startActivity(i);//THIS IS THE ISSUE I THINK
break;
}
}
}
customAdapter = new CustomAdapter(Contacts.this,names,phoneNums,emails);
contactList.setAdapter(customAdapter);